Express Electrical Services: Your Local Electricians Serving All of Southern California
A circuit breaker is a device that cuts off power if the current is too high. In the past, home electrical systems used fuses that would blow if there was an overload. Today, a circuit breaker panel consists of multiple breakers, each serving a different circuit. A breaker can be reset rather than replaced when it trips. Without this protection, electrical overloads could short out or melt electrical wiring, devices, and appliances. The consequences range from expensive damage to potentially deadly fires.
Once electricity enters your home from the power distribution grid, it enters a circuit where there’s a hot wire, connected to the outside energy source, and neutral wire that connects to a neutral source. Although electricity is delivered at a consistent voltage, your light bulbs, appliances, and other electrical devices cause resistance. It’s what enables them to work, but appliances are built so that current is kept below dangerous thresholds, although this isn’t always the case
That’s why homes have circuit breakers, which cut off the circuit when current exceeds safe levels.
How Does a Circuit Breaker Work?
An overload can be corrected by redistributing the load, or by plugging devices into another circuit. However, you don’t have this luxury while an overload is happening. A circuit breaker acts immediately so an unsafe current doesn’t lead to trouble.
Essentially a type of switch, the breaker is connected on both sides by the hot wire to an electromagnet. Electricity that flows through the wire, moving contact, stationary contact, and upper terminal magnetizes the electromagnet. Strong currents cause it to magnetize and pull down a metal lever. This causes the entire linkage to shift and the switch to move the contacts apart, breaking the circuit and cutting off electricity.
Other circuit breaker types have a bimetallic strip instead of an electromagnet. A thin strip of metal is bent by excessive current. Another type contains an explosive material, which when set off by high current, drives a piston to trigger the switch. Advanced designs monitor current and shut down the circuit electronically. A ground fault circuit interrupter is a newer type of breaker specifically designed to prevent electrical shocks, opening the circuit as soon as a current imbalance is detected.
Repairing a Circuit Breaker
Many customers ask about how to repair a circuit breaker. There’s no clear answer because the only way to deal with a faulty breaker is to replace it. This must be done carefully or else you could be burned, shocked, or electrocuted. The breaker replacing the old one must be the same size and voltage, and the power must be turned off, preferably at the main circuit switch. The power will be off throughout your home while repairs are being made.
To replace a breaker, an electrician will loosen the terminal screw to free the breaker’s wires. Exposed wires can be pulled out from the terminal using a pair of needle-nose pliers with rubber insulated handles. The wires should not touch other wires or breakers. The breaker is removed by pulling up on the side so the clips pop out.
The technician will set the new breaker to the “Off” position before sliding its clips into place. The side with the terminals is pushed in first. Once the clips latch to the metal bar in the panel, the electrician will push on the opposite side to lock the breaker. They tighten the terminal screw next while using needle-nose pliers to hold the wires. Then the new breaker can be turned on.